


Star Crossed

by Sincestiel



Series: Tumblr Prompts [8]
Category: Supernatural
Genre: Alpha/Omega, Gender Dysphoria, Knotting, M/M, Sibling Incest, Tumblr Prompt, dean is an alpha but doesn't want to be, kind of, sam is also an alpha and loves dean despite the fact that he shouldn't
Language: English
Status: Completed
Published: 2016-11-20
Updated: 2016-11-21
Packaged: 2018-09-01 04:30:28
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,029
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8607901
Author URL: https://archiveofourown.org/users/Sincestiel/pseuds/Sincestiel
Summary: If only because they’re related, Sam’s scent should turn him off.  But Dean’s wires are all crossed and Sam just smells like the best kind of sin.  And then there’s the fact that Sam is another Alpha.  And, if the brother scent isn’t enough, he should find the stench of arousal from an Alpha stomach turning.  But he doesn’t.





	1. Chapter 1

**Author's Note:**

> I never would have imagined I'd ever write anything even remotely resembling A/B/O. But here we are. This prompt was just too intriguing to pass up.
> 
>  _Wincest: Sam and Dean are both Alphas but Dean has always felt like he should have been an Omega instead. Sam takes care of him_ \
> 
> I tagged this gender dysphoria because I want to make sure to warn for everything. But, if that doesn't feel right here, someone let me know.
> 
> I hope this is suitable. All mistakes are my own. This is really short, but it has potential. So there might possibly be more parts added if there's any real interest shown. idk

Sam’s lips press into the skin behind Dean’s ear, his tongue flicking out to taste, and Dean shivers. He presses his body back into Sam’s bigger frame, begging silently for something he shouldn’t want. But the heat of Sam behind him, the hot slide of Sam’s hard cock against Dean’s balls, pushing into the clutch of Dean’s clenched thighs, has Dean needy for several things that are more than taboo.

His brother, for starters. If only because they’re related, Sam’s scent should turn him off. But Dean’s wires are all crossed and Sam just smells like the best kind of sin. And then there’s the fact that Sam is another Alpha. And, if the brother scent isn’t enough, he should find the _stench_ of arousal from an Alpha stomach turning. But he doesn’t. Sam’s sweat, his precome, the musk of his desire, it all mingles in the air between them and drives Dean so much closer to presenting his ass like a bitch in heat.

And god what he wouldn’t give to actually _be_ a bitch in heat. It’s always felt wrong to him, the fact that he’s an Alpha. He’s always felt not right and twisted in more ways than just the wanting his brother despite the fact that their bodies should discourage it. He hates that they have to use lube when they do this. Misses his slick like a phantom limb. It’s not fair. Not to him and not to the magnificent Alpha currently fingering him open.

That’s another thing. This prep they have to endure every time. His body should prep itself. Sam should be able to bend Dean over and just take. Whenever he wants. And Dean aches to give him that. He wants to be able to offer himself to Sam the way an Omega would. The cloying smell of fake slick, genetically engineered to smell like an Omega in heat, sits heavy in Dean’s nostrils and it physically hurts that it’s not his own.

“Shh,” Sam soothes against Dean’s ear when Dean releases a pained whine, because fuck, this isn’t _right_ , “’S okay, Dean. You’re so good for me, baby. I like it. You know that. I love opening you up to take me. Love how much you want me even when you shouldn’t. Just relax and let me make it good for you. Want me to knot you up? Bend over, baby. Lemme see you.”

Quaking, Dean peels himself off Sam’s sticky, sweaty body and leans over, pressing his torso into the cheap motel mattress and lifting his ass high, hips tilted so Sam can get the best view possible. And he wants to bring his legs together and hide the knot forming between his own thighs, but Sam gently slaps his legs, urging them wider. And when Dean sobs and tries to hide his face in the pillow, embarrassed at his own biology, Sam wraps a gentle hand around Dean’s throbbing knot. He massages Dean’s dick from root to tip and mutters soft encouragement when Dean presses into the cavern of his slick palm.

“Gonna find you a pretty little Omega, Dean. Someone for you to bury that gorgeous cock in while I fuck your sweet ass. Wouldn’t that feel so good?”

Dean nods thinking that not only would it feel good, but it would let him hide the goddamn knot he never wanted in the first place. But he almost forgets all about it in the next breath, because then Sam is using the hand not holding Dean by the dick to run his own tip up and down Dean’s crack. And then he’s pressing in and in and in. All that thick Alpha cock filling Dean up and he lets out a jittery groan and pushes back, encouraging Sam to get as deep as he can.

“ _Sammy_ ,” Dean moans, “Come on. Let me have it all. Fuck me. Make me take your knot. Want it so bad.”

He should be ashamed. Everything in him should revolt at the thought of submitting to anyone. The thought of being knotted, being _bred_ , should make him nauseous, angry even. But he’s desperate for it. He hates knowing that, despite his utter need for this, his body will try to reject the knot that’s pressing just outside his rim every time Sam thrusts into him. But Sammy will get it in. He always does. He forces Dean’s body to comply every goddamn time. So Dean grits his teeth and bears down on Sam’s cock, preparing to help as best he can.

Sam’s thighs slap hard against Dean’s ass and his hands grip tightly to Dean’s hip and his cock. Sam ruts into Dean’s body, driving his cock along Dean’s prostate while working Dean’s knot with practiced ease. It feels so good. Dean takes in a shuddering breath and seesaws between Sam’s hand and his dick. Every time he rides into Sam’s palm he feels a fresh wave of shame rush over him at the thought that Sam has to deal with another Alpha’s knot. But he can’t stop. He needs that pressure too, as much as he hates himself for it. So he keeps his face hidden in the pillow, lets it have all his tears.

“So close, Dean. You ready, baby? Gotta help me out here,” Sam mutters, hips slamming forward and wiggling slightly side to side, like he can pry Dean’s body open enough to take him. And he can. Dean knows this. It won’t last as long as if Dean had an Omega hole because instead of gripping him like Dean _should_ be able to do, Dean’s ass will work to dislodge him. But if they get him deep enough and if Sam stays sealed tightly to him, they can make it last long enough for Sam to pump most of his come into Dean’s channel.

Dean bears down harder, tilts his ass as much as he can, and fucking wills his hole to accept the intrusion. Sam’s hands move back and hold Dean’s cheeks apart, his thumbs pressing into Dean’s rim and pulling it open wider, stuffing his knot into the space they create. And when it finally pops in, Dean squeals at the sudden flash of pain before he melts back into the unrelenting fullness of having his brother’s knot seated in his ass.

Sam pulls him up then, sits Dean on this thighs so the weight of Dean’s body holds his cock where it belongs. And then Sam starts working Dean’s knot in earnest. With Dean splayed like a fucking slutty, greedy Omega over his lap, Sam massages and caresses Dean’s Alpha cock. He knows just how to milk the come out of him and while Sam is shaking and releasing into Dean’s body, he makes sure Dean is spurting into the air, his release spraying in a perfect arc to hit the pillow. His come joins the tears he left there as he shatters in his brother’s arms.

And when it’s all over, when Dean whimpers at the loss of Sam’s knot much sooner than he wants, Sam bundles him up and carries him to the other bed. Sam’s sticky, still leaking cock is pressed between their bodies, snugged against Dean’s ass and Sam’s lips roam sweet and slow over the back of Dean’s neck. He sucks and nibbles, leaving small marks like temporary tattoos over skin they both wish he could claim.


	2. Chapter 2

**Notes for the Chapter:**

> This is a prequel. So, this is actually part one. Sorry if that causes any confusion. But I had a request for backstory and I kind wanted to write this. Idk if this is the end or not.

Dean knows, from a very young age, that he’s an Omega. He knows because of the way he responds to his father’s commands. He knows that his propensity to submit is innate and uncontrollable. He _wants_ to submit even if he blusters and complains about being ordered around. 

And it’s confirmed as far as he’s concerned when he starts having wet dreams. He keeps seeing himself bent over for some big, burly Alpha. He keeps waking in a hot sweat, hard and aching between his legs at the thought of being knotted and tied, big hands holding him tight to a broad chest. When he starts jerking off, he doesn’t stop at fisting his cock. He has to be penetrated to get off. And not just the tip of a finger, like the Alphas in the porn he sometimes watches, do when they jack off. But two fingers and then three and sometimes four. It doesn’t just feel good or add to the experience. He literally can’t come if he isn’t stuffed full. He buys his first knotted dildo before he’s even officially presented, so sure is he that he will present as an Omega. He has to. There’s just no other option.

Except that’s not what happens at all. Instead of waking up and finding himself in the midst of his first heat, leaking slick all over the bed, he reaches down to take care of his insistent morning wood and gasps, jerking his hand back like he’s been burned. The tears are prickling at his eyes before he can even make himself reach between his thighs again and confirm what his sleepy brain is trying to deny.

He hisses when his knuckles scrape over the knot bulging at the base of his cock. It’s hot and heavy and so _full_ and Dean sobs quietly, biting his other fist to keep in the anguished sounds. Because oh god that’s not right.

He pulls his hand away and refuses to touch himself again, despite the utter need that’s sparking from his throbbing balls and pulsing dick. He gets through his first rut without ever getting off. He takes cold showers and ignores his needy body at every turn. And when John suggests he slip out and find a willing Beta or maybe a knot hungry Omega, Dean grits his teeth and declares himself fine. Just fine. Thanks.

The second it’s over, he starts taking the suppressants he’d snatched off a Walgreen’s shelf the morning he’d discovered his body’s ultimate betrayal. They don’t keep his knot from making an appearance, but they keep him from going into rut and dull the urge to bury his knot in the closest Omega. Then he proceeds to fuck his way through almost every Beta he meets. And when the need to be knotted gets too strong, he turns to his toy.

And that’s how he lives for years. It’s how he would have continued to live if not for Sam forgetting his wallet on a food run in the middle of a hunt.

It’s gotten bad. He’s on edge and fucking desperate to be stuffed. Not with a rubber cock, but with the real thing. But he won’t pay for it and he’s never met an Alpha willing to do it for free. Most Alphas are repulsed by even the thought of sleeping with another Alpha, much less knotting one. So he has to find some damn alone time with his toy. He sends Sam out for burgers, waits five minutes just to be sure all is clear, and strips down before digging the long, purple toy out of the bottom of his bag.

He’s so greedy for it, that he’s worked it deep enough to have the knot pressing at his rim by the time Sam comes back through the door. He hasn’t even been gone ten minutes. Just long enough to realize his back pocket is empty.

And there’s Dean, ass in the air, purple dildo sticking out of his hole, flushed and sweaty and desperate. Something happens. Something absolutely unbelievable. Because, instead of leaving, Sam freezes, eyes wandering over Dean’s exposed body, tongue flicking out to wet his lips. And Dean? Dean should cover himself and shout at Sam to give him some damned privacy. But one breath is all it takes and Dean is lost.

The delicious scent of Alpha arousal mixes with the heady scent of home and brother and causes Dean’s ass to clench at the toy and a whine to spill from his mouth as he tries to press it in deeper. Sam drops his jacket and then starts peeling his clothes off as he makes his way to the bed, Dean’s desperation tugging at him like gravity.

“I gotcha, Dean,” Sam says, letting his voice take that deep timbre it only does when he plans on sinking his knot into some random Omega they’ve met at a bar or on a hunt. Dean can’t help it, he shudders and lets the toy fall out of his body. And when Sam climbs onto the bed, still unfastening his jeans, he tosses it aside. “Don’t need that anymore, okay? I knew you we’re struggling, Dean. But why didn’t you tell me it was this bad? We could have done this sooner.”

Dean can hardly believe what’s happening. It’s surreal and he feels like such a goddamn slut bent over for his little brother. But fuck. He needs it. And Sam… well, hasn’t Sam starred in a lot of Dean’s fantasies? Especially since he’s outgrown Dean by several inches and bulked up? He isn’t that much bigger, but it’s enough to make Dean’s body take notice.

“What, exactly, is it that we’re doing?” Dean asks as Sam pulls his jeans and underwear down his thighs. Fuck his cock is big standing out from the baseball sized knot that has already formed at the base. Dean whimpers and raises his ass higher, silently begging.

“I’m going to knot you, Dean. Bury my dick as deep as I can and make that tight little hole of yours accept my knot. And from now on, when you need it, you’re going to come to me and I’m going to take care of you.”

Dean thinks he probably nods, but he can’t be sure because Sam is pushing his cock, slicked with the lube Dean has on the bed from his toy adventures, slowly into Dean’s stretched opening. And fuck. He isn’t wearing a condom. Dean tries to fall forward, away from the intrusion because Sam should be using protection. Dean fucks his way through every town they haunt. But Sam growls and wraps an arm around Dean’s waist, dragging him back and forcing his cock even deeper.

Suddenly Dean can’t breathe, can’t even fight it though he knows he should. Because right now, in this moment, he feels like the Omega he’s always known he is. Sam is holding him tight, not letting Dean resist, stuffing every inch of his Alpha cock into Dean’s body and _making_ him take it. And while Dean knows, realistically, that he could snap Sam out of it, get him to stop if he really needed it, there’s something so animalistic about it that Dean can’t even imagine putting the brakes on.

He whines and arches his back, digs his fingers into the bed and spreads his legs wide. Instincts that should not be his have him presenting himself, trying to make his hole as accessible as possible to his Alpha and he shivers when Sam grunts his praise.

“Good boy, Dean. Such a good little Omega, right, baby? That what you need? Need to have an Alpha take you like a bitch Omega?” 

And how Sam knows that, Dean isn’t sure. But he hits the nail on the head and Dean’s body heats even more, flushing head to toe as he nods and whines his agreement. When Sam growls again, lower, happier, and bites the back of his neck, not claiming – though fuck if Dean doesn’t wish that could be the case – but marking him nonetheless, Dean shivers and fucks back into Sam’s body.

He feels the thick pressure of Sam’s knot nudging against his hole with every thrust and Dean tries to make his body relax. It’s nothing like the toy he’s been using all these years though, and his hole seems to be more willing to accept the softer flesh than the hard rubber of the dildo. It takes them several minutes and a lot of cursing, but eventually Dean feels Sam’s knot invade his body.

Some base part of him sees it like that and tries to scramble away. Some minor Alpha part of his brain that hasn’t ever really caught on. But Dean pushes that slight repulsion away and then it’s just a fucking glorious revelation. It feels right, being tied to Sam, knotted and owned. Dean cries out in utter joy when Sam pulls him flush against his pelvis and locks them together, big, wide hands bruising Dean’s hips with their determined grip.

“Gotta stay still, Dean. If you want to keep it in, you’ve got to be still,” Sam mutters, face planted between Dean’s shoulder blades.

“Yeah,” Dean says, urgent and breathless, “stay in, Sammy. God, please.”

He sounds raw and blissed out and he shivers when Sam presses the sweetest kiss over Dean’s heated, sweaty skin. It doesn’t last long. He feels his body, against his will, working to eject Sam’s knot. But, for those few minutes, Dean feels like he’s exactly where he belongs. For the first time since he felt his knot, swollen and wrong, he feels content and happy.

When Sam slips free, his come drizzling out of Dean’s well fucked hole and sliding down his balls, he thumbs at the loose, sloppy opening. He tells Dean how perfect and beautiful he looks, what a perfect Omega he is, as he massages the rest of his come out over Dean’s crack. And then he rolls Dean over and without even a hint of disgust, he takes Dean’s Alpha cock into his mouth and sucks him off. He spends almost fifteen minutes draining Dean’s knot and Dean breaks under Sam’s ministrations. He’s never allowed himself that pleasure, never given in to that desire with someone else.

Afterward, Sam fits himself to Dean’s side, taking Dean’s mouth in a soft, slow kiss for the first time. He tells Dean there’ll be no one else anymore. Promises that he’ll take care of all of Dean’s needs and makes Dean promise the same. It’s not so much a discussion as it is Sammy issuing an order and Dean obeying. Just like that. And Dean’s universe doesn’t seem quite so off kilter anymore.

**Author's Note:**

> Customary tumblr plug: Hey, if you wanna follow me on [tumblr](http://sincestiel.tumblr.com/) that would be alright. Shoot me an [ask](http://sincestiel.tumblr.com/ask) if you have a prompt (Destiel, Wincestiel, Wincest, Cockles, J2) and we'll see what happens. :)


End file.
